1. Technical Field
The present invention generally relates to a movable assembly with resilient function, to micro actuators, and to camera modules that employ micro actuators.
2. Discussion of Related Art
With the rapid development of optical imaging technology, lens modules are now widely used in a variety of electronic devices, such as digital cameras and mobile phones.
To achieve focusing capability in micro camera modules, a micro actuator is employed to move one or more lens groups in the micro camera module. Generally, a micro actuator includes a moveable member, a driver configured to apply a force to the moveable member thereby moving the moveable member, and several resilient members for resetting the moveable member to its original position. The resilient members can be spring plates, which are made by etching a copper or a silicon plate. For each spring plate, a high depth-width ratio of the precursor copper or silicon plate is required to provide the needed stability and resilient force of the spring plate finally produced. However, if the width of the precursor copper or silicon plate is large, the etching process can be unduly difficult. In addition, if the width of the precursor copper or silicon plate is large, a volume of the spring plate is correspondingly large, which militates against the trend toward miniaturization of micro actuators.
Therefore, there is a need to overcome the aforementioned problems.